Genotypic Characterization and Antimicrobial Susceptibility of HumanCampylobacter jejuniIsolates in Southern Spain

Abstract

AbstractCampylobacter jejuniis the main cause of bacterial gastroenteritis and a public health problem worldwide. Little information is available on the genotypic characteristics of humanCampylobacter jejuniin Spain. This study is based on an analysis of the resistome, virulome and phylogenetic relationship, antibiogram prediction and antimicrobial susceptibility of 114 human isolates ofC. jejunifrom a tertiary hospital in southern Spain from October 2020 to June 2023. The isolates were sequenced using Illumina technology, and bioinformatic analysis was subsequently performed. The susceptibility ofC. jejuniisolates to ciprofloxacin, tetracycline, and erythromycin was tested. A high resistance rate was obtained for ciprofloxacin (90.6%) and tetracycline (66.7%), and a low resistance rate for erythromycin (0.85%) was detected among theC. jejuniisolates. CC-21 (n=23), ST-572 (n = 13) and ST-6532 (n=13) were the most prevalent clonal complexes (CCs) and sequence types (STs). Concerning the virulome, thecadF, ciaB, andcdtABCgenes were detected in all the isolates. A prevalence of 20.1% was obtained for the geneswlaNandcstIII, which are related to the pathogenesis of Guillain-Barré syndrome (GBS). The prevalence of the main antimicrobial resistance markers detected werecmeABC(92.1%),RE-cmeABC(7.9%), the T86I substitution ingyrA(88.9%),blaOXA-61(72.6%), tet(O)(65.8%) andant(6)-Ia(17.1%). High antibiogram prediction rates (>97%) were obtained except for the erythromycin-resistant phenotype. This study contributes significantly to the knowledge ofCampylobacter jejunigenomics for the prevention, treatment and control of infections caused by this pathogen, which is relevant to public health.ImportanceDespite being the pathogen with the greatest number of gastroenteritis cases worldwide,Campylobacter jejuniremains a poorly studied microorganism. The development of whole-genome sequencing (WGS) techniques has led to a better understanding of the genotypic characteristics of this pathogen. These techniques complement the data obtained from the phenotypic analysis ofC. jejuniisolates. The zoonotic transmission ofC. jejunithrough the consumption of contaminated poultry implies approaching the study of this pathogen through the term “One Health.” This is the first study, using WGS, conducted on human isolates ofC. jejuniin Spain to date, which allows comparison of the results obtained with similar studies conducted in other countries and with animal and environmental isolates.